condition mean min max ZT0-3 0.641322 0.2963875 0.8450394999999999 ZT4-7 0.6080795 0.6080795 0.6080795 ZT8-11 0.83815 0.83815 0.83815 ZT12-15 1.8151475 1.6608399999999999 1.969455 ZT16-19 2.1180849999999998 2.1180849999999998 2.1180849999999998 ZT20-23 2.536665 2.536665 2.536665